DE112016003022T5 - Superconducting wire - Google Patents

Abstract

The present invention relates to a superconducting wire whose electrical and physical properties are improved.

Description

Field of the invention

The present invention relates to a superconducting wire. In particular, the present invention relates to a superconducting wire, also referred to as superconducting wire, whose electrical and physical properties are improved.

State of the art

In the superconducting wires, the electric resistance approaches zero at the constant temperature, and therefore the superconducting wires have a large current transfer capability even at the low electric voltage.

In the superconducting wires having such superconducting wires, the methods for cooling the cable by means of a refrigerant such as nitrogen, etc. by means of which kyrogenic environments can be formed and maintained, and / or the heat insulating methods by means of which vacuum layers can be formed are usually used , used.

Are the superconducting wires used to construct a previously proposed superconducting cable wound up to make a drum, etc. in a state where they are wound spirally on an outside of a molded body, etc., or the superconducting cable is wound into a drum bent a Verlegungsstrecke, then permanent tension or twists could be exercised, thereby resulting stress the problems such. B. the interruption or the like could cause only the thickness of about 0.1 mm having superconducting wires. In particular, because the cost portion of the superconducting wires is largest of the components of the entire cable, durability or physical reliability of the superconducting wires is required.

Further, in the situations where the physical stresses such as strains or twists, etc., are exerted, the superconducting wires are simply not allowed to be destroyed or deformed, and their stable electrical properties must be moreover ensured.

Disclosure of the invention

Technical task

The invention is therefore based on the object to provide a superconducting wire whose electrical and physical properties are improved.

Technical solution of the task

To achieve the object, according to the invention, a superconducting wire is proposed which has a width of 0.4 mm to 0.5 mm and a thickness of 0.3 mm to 0.5 mm, and using a superconducting material such as YBCO or ReBCO (Re = Sm, Gd, Nd, Dy, HO) is prepared, wherein its threshold current (DC Ic) in the self-field at a temperature of 77 K under atmospheric pressure of 1 bar 150 A to 500 A can be.

Here, it may be provided that after the above superconducting wire has been successively bent by two rolls each having a diameter of 35 mm, its threshold current when applying a bending load may be 95 percent or more of the above threshold current.

Further, it may be arranged that the above superconducting wire is formed such that after being successively bent by four rolls each having a diameter of 50 mm, its threshold current when applying a double bending load is also 95 percent or more of the above threshold current can.

And, it may be arranged that the above superconducting wire is formed such that its threshold threshold current when applying a longitudinal clamping force of 250 MPa or a longitudinal clamping force to it by 0.2 can also amount to 95 percent or more of the above threshold current.

In addition, it may be arranged that the above superconducting wire is formed such that its torsional threshold current in a state of being twisted 200 mm apart in a longitudinal direction may also be 95% or more of the above threshold current.

Further, it may be also provided that a threshold current of the above superconducting wire when applying a load of 3 kg to 8 kg to this superconducting wire in a longitudinal direction thereof in a state in which this superconducting wire on a shaped body of the superconducting cable with a slope of more or less 220 mm, may be 95 percent or more of the above threshold current.

Furthermore, it can be provided that the above superconducting wire is formed such that a plurality of wires are joined together with a unit of 200 m to 400 m, wherein an electric Resistance of a joint may be 200 nΩ or less.

Here, it may be provided that a joint resistance of the joint is selected such that this joint resistance per joint to which the load of 3 kg to 8 kg is applied in a longitudinal direction in a state where the above superconducting wire is applied to a molded body of the superconducting cable is wound at a pitch of more or less 220 mm, 240 nΩ or less, or increased by 20 percent or less against a joint resistance of a normal condition.

Here, it may be provided that the above superconducting wire is formed so that its threshold current in a state where it is immersed in a liquid nitrogen at the atmospheric pressure of 30 atm for 16 hours may also be 95 percent or more of the above threshold current.

Furthermore, it can be provided that a gradient of an electrical voltage with respect to an electric current that is equal to or greater than the above threshold current is 25 to 30.

Further, it may be provided that an AC loss of the above superconducting wire is 0.4 W / kA · m or less.

To achieve the above object, the present invention can provide a superconducting wire having a width of 0.4 mm to 0.5 mm and a thickness of 0.3 mm to 0.5 mm, and using a superconducting material How YBCO or ReBCO (Re = Sm, Gd, Nd, Dy, HO) is prepared, characterized in that a threshold current (DC Ic) in the self-field at a temperature of 77 K under atmospheric pressure of 1 bar 150 A to 500 A; That is, a threshold current satisfactorily reaches 90 percent or more of the above threshold current (DC Ic) in the following cases: namely, in the case where a bending load after the successive turn of the above superconducting wire is caused by two rollers each having a diameter of 35 mm is applied, or in which a double bending load after the successive directional bending of the above superconducting wire by means of four rolls each having a diameter of 50 mm is applied, or in which a longitudinal clamping force of 250 MPa or 0.2% extending the wire longitudinal clamping force is applied to the above superconducting wire, or in which the above superconducting wire is twisted at a pitch of 200 mm in a longitudinal direction, or at a load of 3 kg to 8 kg in a state in which this superconducting wire on a shaped body of the superconducting cable with a slope of more or less around 2 20 mm is wound on the above superconducting wire in a longitudinal direction thereof or in a state where the above superconducting wire is immersed in a liquid nitrogen in which an internal pressure of about 30 atm is maintained for 16 hours; that the above superconducting wire is formed so as to join a plurality of wires having a unit of 200 m to 400 m, with an electrical resistance of a joint 200 nΩ or less, and wherein the joint resistance of the joint is selected such that this joint resistance one joint at which the load of 3 kg to 8 kg is applied in a longitudinal direction in a state where the above superconducting wire is wound on the molded body of the superconducting cable at a pitch of more or less by 220 mm, 240 nΩ or is less, or increased by 20 percent or less, compared to a joint resistance of a normal condition; that a gradient of an electric voltage to an electric current equal to or greater than the above threshold current is 25 to 30; and that an AC loss of the above superconducting wire is 0.4 W / kA · m or less.

To achieve the above object, the present invention can further provide a superconducting wire having a width of 0.4 mm to 0.5 mm and a thickness of 0.3 mm to 0.5 mm, and using a superconducting wire Material, such as YBCO or ReBCO (Re = Sm, Gd, Nd, Dy, HO) is produced, characterized in that the inflation of the above superconducting wire in a state in which this in a liquid nitrogen, wherein an internal pressure of about 30 atm is maintained, immersed for 16 hours, is not visually observed.

To achieve the above object, the present invention can further provide a superconducting wire having a width of 0.4 mm to 0.5 mm and a thickness of 0.3 mm to 0.5 mm, and using a superconducting material, such as YBCO or ReBCO (Re = Sm, Gd, Nd, Dy, HO), characterized in that a threshold current (DC Ic) in the self-field at a temperature of 77 K under atmospheric pressure of 1 bar 150 A to 500 A. is; That is, a threshold current satisfactorily reaches 90% or more of the above threshold current (DC Ic) in the following cases: namely, in the case where a bending load after the successively turning the above superconducting wire by means of two rollers each having a diameter of 35 mm is applied, or in which a double bending load after the successive directional bending of the above superconducting wire is applied by means of four rollers each having a diameter of 50 mm, or in which a longitudinal clamping force of 250 MPa or a longitudinal clamping force extending the wire by 0.2 is applied to the above superconducting wire or the above superconducting wire twisted 200 mm in a longitudinal direction, or in which a load of 3 kg to 8 kg in a state in which this superconducting wire is wound on a shaped body of the superconducting cable with a pitch of more or less by 220 mm, is applied to the above superconducting wire in a longitudinal direction thereof or in a state where the above superconducting wire is immersed in a liquid nitrogen in which an internal pressure of about 30 atm is maintained for 16 hours; that the above superconducting wire is formed so as to join a plurality of wires having a unit of 200 m to 400 m, with an electrical resistance of a joint 200 nΩ or less, and wherein the joint resistance of the joint is selected such that this joint resistance one joint at which the load of 3 kg to 8 kg is applied in a longitudinal direction in a state where the above superconducting wire is wound on the molded body of the superconducting cable at a pitch of more or less by 220 mm, 240 nΩ or is less, or increased by 20 percent or less, compared to a joint resistance of a normal state; that a gradient of an electric voltage to an electric current equal to or greater than the above threshold current is 25 to 30; that an AC loss of the above superconducting wire is 0.4 W / kA · m or less; and that the inflation of the above superconducting wire in a state of being immersed in a liquid nitrogen in which an internal pressure of about 30 atm is maintained for 16 hours is not visually observed.

Favorable effect of the invention

In a superconducting wire according to the present invention, the physical properties of the superconducting wire can be increased so that it can endure the physical stresses such as cocking force and twisting, etc., which may be applied to the superconducting wire during the manufacturing and laying operation ,

In a superconducting wire according to the present invention, the physical strength of the superconducting wire can be enhanced so that the destruction, etc. of the superconducting wire can be prevented while ensuring both the physical strength against the physical stress and the electrical properties together ,

By means of a superconducting wire according to the present invention, the physical strength of the superconducting wire during the manufacturing, laying and application operation of the superconducting cable can be improved while ensuring the electrical properties, so that the manufacturing cost due to the elimination, etc. of Superconducting wire can be saved considerably.

Brief description of the drawings

Show it:

1 a stepwise stripped state of a superconducting wire according to the present invention in a perspective view;

2 a sectional view of a superconducting cable 1 ;

3 an example of a superconducting wire that can be applied to a superconducting cable;

4 the sectional views of some examples of a superconducting wire, which can be applied to the superconducting wire according to the present invention;

5 a testing device for bending testing the superconducting wire according to the present invention;

6 a diagram of a voltage depending on a current applied to the superconducting wire current; and

7 a tester for testing a hermeticity of the superconducting wire according to the present invention.

Preferred embodiments of the invention

Hereinafter, the preferred embodiments of the present invention will be explained in more detail with reference to the accompanying drawings. However, the invention should not be limited to the embodiments explained here and can be implemented concretely in other embodiments. Rather, the embodiments proposed here are therefore intended to fully and completely carry out the disclosed contents and to be able to sufficiently transfer the idea of the invention to a person skilled in the art. Throughout the description of the present invention, like components are also provided with like reference numerals.

1 shows a stepwise stripped state of a superconducting wire according to the present invention in a perspective view, wherein 2 a sectional view of a superconducting cable 1 shows.

Hereinafter, a basic structure of a superconducting cable to which a superconducting wire (also referred to as superconducting wire) according to the present invention is applied will be explained.

The superconducting, in 1 The cable shown may include the following features: a core 100 , which is a shaped body 110 , a superconducting conductor layer 130 which consists of at least one layer comprising a plurality of superconducting wires, which are so in the longitudinal direction of the molding 110 are arranged side by side, that they are an outer side of the molding 110 can wrap around, an insulating tape 140 that is the superconducting conductor layer 130 wrapped, and a superconductive shielding layer 180 which consists of at least one layer comprising a plurality of superconducting wires, which are so in the longitudinal direction of the molding 110 are arranged side by side, that they are an outer side of the insulating tape 140 wrap around; a cooling part 200 which is for cooling the core 100 on an outside of the core 100 provided and with a refrigerant circuit of a liquid refrigerant for cooling the core 100 is provided; an inner metal tube 300 on the outside of the refrigerator 200 is provided; a thermal insulation part 400 which is on an outside of the inner metal tube 300 is provided and forms a thermal barrier coating which is shaped such that a thermal insulation material 401 multilayered wound; a vacuum part 500 that is several of an outside heat-insulating part 400 spaced spacers 560 has to the cooling part 200 to be able to thermally isolate under vacuum; an outer metal tube 600 that on an outside of the vacuum part 500 is provided; and an outer jacket 700 which is on an outside of the outer metal tube 600 is provided and thus forms Ummantelungslage.

Subsequently, the respective components of the superconducting cable are successively analyzed: the molded article 110 is flat and can offer a space that serves to shape the body 110 to mount the flat, long superconducting wires, and at the same time serve as a frame for forming a shape for mounting such superconducting wires, and besides, can become the path through which an electric leakage current flows. Furthermore, the shaped body 110 have a shape formed such that a plurality of copper (Cu) conductor strands 111 are also circularly compressed with a circular cross-section.

More specifically, the molded article is 110 basically circular cylindrical and serves as a frame which is designed such that flat, long superconducting wires can be placed on this frame. The diameter of the molding 110 taking into account the width of the superconducting wires dimensioned such that these superconducting wires are not chipped off each other and when placing them on each other on the molding 110 as close as possible to a circular shape.

As in 1 and 2 As shown, the above molded article may be designed such that its center is formed in a solid shape, wherein the molded article 110 however, may also be in the form of a hollow pipe, so that it can perform both a role as a framework for placing the superconducting wires on itself and at the same time as a path for guiding a refrigerant within itself, the respective ones Shaped body strands 111 made of copper, etc., and wherein the respective strands are connected in parallel to the respective superconducting wires, so that they serve as a return conductor in the occurrence of an electrical fault current due to a short circuit (extinction, lightning, insulation destruction, etc.) of a power supply system in the power grid can.

The roll as a return conductor in the emergence of the electrical fault current in the power grid can by the conductor strands 111 However, they are also taken over by an electrically conductive layer of a normal temperature at an own electrical conductivity metal attached to the respective superconducting wires, as described later. The electrically conductive layer may have a shape of a metal band. This will be explained in more detail below.

Depending on the capacity of the electrical fault current, a cross-sectional area of a conductor, such. As copper, etc., which forms a strand, be determined, wherein be high electrical voltage, the copper strands can be compressed in a circle and thus formed in a stranded form.

As described below, the superconducting wire according to the present invention is provided on both surfaces thereof with the electrically conductive layer of a metal having an electric conductivity at normal temperature so that its mechanical rigidity can be enhanced. This electrically conductive layer can be strengthened by increasing the mechanical rigidity of the superconducting wire at the break, etc. due to the twisting tension prevent the winding of the superconducting wire.

Since these electrically conductive layer reinforce the mechanical rigidity of the superconducting wire and at the same time together with the molded body, the role as the way back of the electrical fault current in the occurrence of the accident, such. Short circuit, etc., can perform their role, the molded body of the superconducting cable on which the superconducting wire according to the present invention is applied may have a smaller diameter than the other molded body, i. H. which builds a previous, general superconducting cable, which will be discussed in more detail later.

As several pieces of the the molded body 110 building up conductor strands 111 are formed with a circular cross section in eienr circularly compressed and stranded form, the surface of the molding 110 necessarily be just uneven. So that the uneven surface of the shaped body 110 Smoothing can be a smoothing layer 120 on the outside of the molding 110 be sheathed. For this smoothing layer, a material such. As semiconducting carbon paper or brass band, etc. are used.

Between the smoothing layer 120 and the superconducting conductor layer 130 a cushion layer may additionally be provided, this not being shown in the figures. The cushion layer is made by means of a semiconducting carbon paper tape and may be provided for the protection of the superconducting conductor layer.

Further, on the outside of the molded body smoothed by the smoothing layer 110 a first superconducting conductor layer 130a be provided, which is formed by the wrapping of the plurality of superconducting wires as a layer. This first superconducting conductor layer 130a may be disposed such that the plurality of superconducting wires adjacent to each other adjacent to each other has a periphery of the smoothing layer 120 can wrap around.

As in 1 shown, the superconducting conductor layer 130 Also, depending on the capacity of a superconducting cable to be transmitted or distributing electrical power multilayered.

When in 1 In the embodiment shown, it is shown that a superconducting conductor layer consists of two layers in total 130a and 130 b is provided.

If the superconducting conductor layer is provided in multiple layers, an insulating tape can be used 140 between the superconducting conductor layers 130a and 130 b be provided. The reason why the electrical tape 140 between the superconducting conductor layers 130a and 130 b is to provide a directional characteristic of a current through the superconducting conductor layers constituting each layer 130a and 130 b to be able to control, because if no electrical tape 140 is provided, then a current flow is scattered and thus the current can not flow in an intended direction. But can the electrical tape 140 essentially causing the current carrying directions of the multilayer stacked superconducting conductor layers to coincide with each other.

Is the electrical tape 140 also provided as an alternative, then the skin effect of the superconducting wires constituting each superconducting conductor layer can be additionally prevented.

When in 1 In the embodiment shown, an example is shown in which the superconducting conductor layer 130 of two layers, ie the first superconducting conductor layer 130a and the second superconducting conductor layer 130 b but, if necessary, more than two superconducting conductor layers can be provided.

Furthermore, the respective superconducting wires can be any superconducting conductor layer 130a respectively. 130 b build up, parallel to the respective strands that form the body 110 build, be connected. The reason for this is to avoid the electrical current flowing through the superconducting wires in accidents such. As short circuit (extinction, flash, insulation destruction, destruction of the superconducting condition, etc.) as electrical fault current to the strands of the molding 110 to distribute. In this way, the heat generation or damage, etc. of the superconducting wires can be avoided.

In addition, an inner semiconductive layer 150 on an outer side of the second superconducting conductor layer 130 b be provided, which on an outer side of the first superconducting conductor layer 130a is provided. In this case, the inner semiconducting layer 150 for relaxing an electric field concentration per region of the superconducting conductor layer 130 and to homogenize an electric field of a surface. More specifically, it may be provided for relaxing the electric field concentration resulting in the corner region of the superconducting wires and for homogenizing an electric field distribution. This also applies to the outer half-conductive layer to be explained later 170 ,

The inner semiconducting layer 150 may be provided such that a semiconducting tape is wound.

In addition, an insulating layer 160 on the outside of the inner semiconductive layer 150 be arranged. This insulating layer 160 may be provided to increase an insulation resistance of the superconducting cable. Generally, a cross-linked polyethylene (XLPE) or an oil cable is used to insulate a high voltage cable, but there is a problem that the superconducting cable is cooled to a cryogenic temperature for superconductivity at the cryogenic temperature, the cross-linked polyethylene is damaged, which may lead to insulation damage, and the oil cable may cause an environmental problem, etc., and therefore the superconducting cable of the present invention is an insulating paper made of ordinary paper as an insulating layer 160 can use, with this insulating layer 160 can be designed so that the insulating paper is wound several times.

In this case, a kraft paper or polypropylene lamella rapier (English: PPLP, Polypropylene Laminated Paper) is mainly used as insulating paper. For the superconducting cable of the various paper-insulated materials, the polypropylene laminate paper is prepared in consideration of the characteristics such B. simplicity of turns, insulation, etc. used.

Furthermore, the outer semiconductive conductor layer 170 on the outside of the insulating layer 160 be provided. The outer semiconductive conductor layer can also be used to relax an electro-field concentration per region of the superconducting conductor layer 130 and for homogenizing an electric field of a surface, wherein also the outer semiconductive layer 170 may be provided such that a semiconducting tape is wound.

In addition, a superconductive shielding layer 180 on an outer side of the outer semiconductive layer 170 be provided. In this case, the method of forming the superconducting shield layer 180 as well as the method of forming the superconducting conductor layer 130 be. Is a surface of the outer semiconductive layer 170 uneven, then a smoothing layer may be provided as needed, the superconducting wires for forming the superconductive shielding layer 180 may be arranged next to each other in the circumferential direction on an outer side of the smoothing layer.

At this time, an electric current flowing through the shield layer composed of the second-generation superconducting wires is dimensioned to be about 95% of an electric current flowing through the superconducting conductor layer, so that stray magnetic field can be minimized.

Further, on an outer side of the superconductive shield layer 180 a core coating layer 190 be provided for the deficiency of the core 100 can serve. This core sheath layer 190 can have any kind of bands or binders, etc., where it can serve as an outer jacket, thus the core 100 a subsequent described cooling layer is exposed, as well as simultaneously to connect all the components of the core 100 can serve, and where they are made of a metallic band, such. B. may consist of SUS material.

That way, the core can 100 of the superconducting cable, wherein the smoothing layer and the semiconductive layer are in 1 and 2 are formed as a single layer of the same material, but depending on requirements, different auxiliary layers can be additionally provided.

In addition, a refrigerator can 200 on an outside of the core 100 to be appropriate. This refrigerator part 200 can be used to cool the superconducting wires of the core 100 be provided, it may be provided in its inside with a circulation circuit of a liquid refrigerant. As the liquid refrigerant, a liquid nitrogen may be used, and this liquid refrigerant (ie, liquid nitrogen) circulates the cooling circuit in a cooled state where it has a temperature of -200 ° C, and thus a superconducting condition of the core 100 superconducting wires provided inside the cooling part, ie, can maintain a cryogenic condition.

It can be in the refrigerator 200 provided cooling circuit can flow the liquid refrigerant in one direction, said refrigerant collected by means of a junction box, etc. of the superconducting cable, cooled again and then back to the cooling circuit of the cooling part 200 can be supplied.

Furthermore, an inner metal tube 300 on an outside of the cooling part 200 to be appropriate. Here, the inner metal tube is used 300 together with a later-mentioned outer metal tube 600 as the outer sheath of the superconducting cable, thus causing mechanical damage to the core 100 can be prevented during installation and operation of the superconducting cable. In general, that will Superconducting cables are wound on a drum for easy manufacture and transport, and then unwound from the drum during installation, allowing flexural or tensile stress to be exerted permanently on the superconducting cable.

So that the output power can be maintained even in the situation in which this mechanical stress is exerted, the inner metal tube 300 be provided. Therefore, the inner metal tube 300 have a corrugated structure for enhancing a rigidity against the mechanical stress, in which the elevations and depressions are repeated in the longitudinal direction of the superconducting cable, wherein the inner metal tube 300 thus made of a material such. As aluminum, etc. may exist.

Because the inner metal tube 300 on the outside of the refrigerator 200 is attached, it may be cryogenic according to the temperature of the liquid refrigerant. Therefore, the inner metal tube 300 classified as cryogenic metal tube.

Further, on the outer circumference of the inner metal tube 300 a thermal insulation part 400 to be mounted, which has a heat-insulating layer, which is formed such that a heat-insulating material, which is formed by the thin coating with a polymer having low thermal conductivity, is wound multilayered on a metal layer with high reflectivity. The thermal barrier coating forms a multi-layer insulation (English: MLI, multi-layer insulation) and can thus block the heat penetration into the inner metal tube 300 be provided.

Because the inner metal tube 300 especially made of metal and thus the heat penetration or heat exchange can be easily done by the Konduktion, the thermal insulation part 400 mainly to minimize the heat exchange or the heat penetration by the conduction, whereby also due to the material of the metal layer with high reflectivity, an effect for preventing the heat exchange or the heat penetration by the radiation can be achieved.

And can the number of layers of the thermal insulation part 400 to minimize heat penetration. When it is composed of many layers, an effect of blocking a radiant heat is increased, but an effect of blocking a conduction heat and a heat-blocking effect by the convection are reduced due to the thinner thickness of a vacuum layer, therefore, it is important to use the appropriate number of layers.

Furthermore, a vacuum part 500 on an outside of the thermal insulation part 400 to be appropriate. In this case, the vacuum part 500 to minimize heat transfer due to convection, etc., in the direction of the thermal barrier coating, which is insufficient thermal insulation by means of the thermal barrier panel 400 can arise.

Next to it is the vacuum part 500 a clearance space from the outside of the heat-insulating part 400 so that it can be configured by means of the method for vacuuming the distance space.

Here, the vacuum part 500 at least one spacer 560 for forming a physical clearance space, which spacer may serve as a clearance space provided for preventing the heat infiltration by the convection, etc., from the exterior at a normal temperature to the side of the core. To ensure that a contact between the outer metal tube 600 at an outside of the distance space in the vacuum part 500 is provided, and the thermal insulation part 400 within the vacuum part 500 can be prevented over the entire range of superconducting cable, at least one spacer 560 Further, be provided in the spacer space, wherein the number of these spacers can be increased or decreased more precisely depending on the type or size of the superconducting cable or spacer. In this regard, it is shown that in 1 and 2 illustrated superconducting cables 1000 has four spacers, but the number of these spacers can be increased or decreased.

The spacers can 560 be arranged along the longitudinal direction of the superconducting cable, through these spacers, the outside of the core 100 , even more precisely the thermal insulation part 400 Spiral or circular wound can be wound.

Regarding the number of spacers 560 For example, the superconducting cable according to the present invention may have 3 to 5 spacers. In this case, the spacers can prevent the heat exchange due to the Konduktion by forming a distance space, wherein the structure of the spacers can be configured one or more layers.

Furthermore, the material of the spacers 560 a resin, e.g. As polyethylene (PE).

Furthermore, the spacer 560 as required from a fluororesin (eg polytetrafluoroethylene (English: PTFE, Poly Tetra Fluoro Ethylene; Teflon (trademark)), or its back surface, which consists of a conventional resin (eg polyethylene), are coated with the fluororesin (eg polytetrafluoroethylene).

In this case, the polytetrafluoroethylene as a type of fluorine resin due to a strong chemical combination between a fluorine and a carbon form a very stable compound, so that it has the good properties such. B. has almost complete chemical inactivity, heat resistance, non-adhesive strength, good insulating security, low coefficient of friction or the like.

Furthermore, the polytetrafluoroethylene has a certain flexibility, which is why it is the thermal insulation part 400 spirally wound in the longitudinal direction of the superconducting cable can be wound, while it also has a certain strength, which is why it acts as a spacer to prevent the contact between the heat-insulating part 400 and the outer metal tube 600 to be used and to physically maintain the vacuum part 500 can serve constructive distance space. The diameter of the spacer 560 can be 4 mm to 8 mm. Furthermore, the cross section of the spacer 560 in different forms, such as B. circular shape, triangle, square, star, etc. may be formed.

It can also be an outer metal tube 600 on an outside of the with the spacers 560 provided vacuum part 500 to be appropriate. Dabeil can the outer metal tube 600 have the same shape or consist of a same material, such as the inner metal tube 300 , wherein the outer metal tube 600 has a larger diameter than the inner metal tube 300 so that it is possible through the spacers 560 to form a distance space. On these spacers 560 will be discussed later.

In addition, also on an outer side of the outer metal tube 600 an outer jacket 700 be attached, which takes over a sheath function for protecting the interior of the superconducting cable. It can be used as the material of the outer jacket 700 a sheath material may be used, which is the outer sheath 700 a usual power supply cable builds. The outer jacket 700 can the corrosion of the inner metal pipe 600 prevent etc. or avoid the damage of the cable by the external force. It can be made of a material such. As polyethylene (PE), polyvinyl chloride (PVC), etc. exist.

3 shows an example of a superconducting wire that can be applied to a superconducting cable. Still more detail shows 3 (a) a sectional view of the existing superconducting wire 131 without an electrically conductive layer while 3 (b) the superconducting wire 131 shows, to which an electrically conductive layer of a metal having normal conductivity at an electrical conductivity is attached.

Since the superconducting wire constituting the superconducting wire is spirally wound in the longitudinal direction of the superconducting cable, and thus a torsional stress is permanently applied to the superconducting wire, the interruption of the superconducting wire may occur during the manufacturing or winding operation of the superconducting cable, whereby the superconducting cable in the accidents, such as As short circuit (extinction, flash, Isolationsyerstörung, destruction of the superconducting condition, etc.) the shaped body 110 used as the return conductor, as mentioned above.

Since the superconducting wire according to the present invention is provided on both surfaces thereof with the electrically conductive layer me1 and me2, respectively, of a metal having an electric conductivity at normal temperature and thus offers an effect of enhancing mechanical rigidity of the superconducting wire itself, and at the same time the electrically conductive one Layer me1 or me2 performs a function as a return conductor when the short-circuit accident of a superconducting system is formed together with the molded body, the diameter of the molded body can be compared to the superconducting cable to which the superconducting wire without the electrically conductive layer me1 or me2 is applied. be reduced, so that an effect can be obtained to reduce the diameter and the weight of the entire superconducting cable. This will be analyzed in more detail below.

In this regard, the in 3 (a) The conventional superconducting wire shown in FIG. 1 has a width of x (mm) and a thickness of y (mm) while that in FIG 3 (b) shown superconducting wire according to the present invention is formed such that provided on the two surfaces of the conventional superconducting wire in each case a metal material and then also each an electrically conductive layer me1 or me2 with a width of x (mm) and thickness of y (mm ) up to 2y (mm) is applied additionally.

Therefore, the superconducting wire 131 according to the present invention be designed so that on the existing superconducting wire 131 ' an electrically conductive layer having a thickness of y (mm) to 2y (mm) is applied, so that a total thickness may be 3y (mm) to 5y (mm).

As a superconducting wire used in the below-mentioned experiment was a superconducting wire having a width of 0.4 mm to 0.5 mm and a thickness of 0.3 mm to 0.5 mm, that is, y = 0.1.

Thereby, the electrically conductive layer may be attached to the existing superconducting wires by means of the soldering, as mentioned later.

If the electrically conductive layer me1 or me2 by means of the soldering respectively on the two surfaces of the existing superconducting wires 131 is attached and the lateral side of the respective superconducting wires 131 is soldered or the whole surfaces of the superconducting wires 131 be clad with metal, then the fault current in the occurrence of the accident, such. As short circuit, etc., both on each parallel to the respective superconducting wires strands of the molding 110 are distributed as well as on the attached to the respective superconducting wires, electrically conductive layer, which is why this electrically conductive layer me1 or me2 can take over together with the molding the role as a return conductor.

Although the respective electrically conductive layer me1 or me2 has a width of x (mm) and a thickness of y (mm) to 2y (mm), it is further formed on the two surfaces of the superconducting wires having an existing thickness of y (mm). Therefore, in this case, the electric conductivity becomes larger due to the skin effect, etc., than in the case where the electrically conductive layer having a thickness of 2y (mm) to 4y (mm) is formed on only one surface of the existing one Superconducting wires is added.

If the electroconductive layer is attached to each of the two surfaces of the superconducting wire, the separation phenomenon of the electroconductive layer in bending the superconducting wire can be minimized, and thus the rigidity can be better enhanced than in the case where the electroconductive layer is only on one surface is added to the existing superconducting wire, and it may also be favorable when using the electrically conductive layer as the return conductor, in each case attach the electrically conductive layer on the two surfaces of the superconducting wire and also to reduce the diameter of the shaped body.

If the thickness of the respective existing superconducting wires is about 0.1 mm while the thickness of the respective electrically conductive layers is about 0.1 to 0.2 mm, then the thickness of the superconducting wire according to the present invention may be 0.3 to 0.5 mm, so that it could be considered that the thickness of the respective superconducting wires according to the present invention would be increased in comparison with that of the respective existing superconducting wires on a large scale. However, the thickness of each of the improved superconducting wires is only one level of the thin film, and thus their influence on the whole thickness of the superconducting cable is not large. Nevertheless, the cross-sectional area of the molded article in which the uninsulated strands are formed in a very compact shape as mentioned above can be reduced by 10% to 40%.

Thus, according to the present invention, the superconducting wire having a width of 0.4 mm to 0.5 mm and a thickness of 0.3 mm to 0.5 mm can be provided, and using a superconducting material such as YBCO or ReBCO (FIG. Re = Sm, Gd, Nd, Dy, HO) is prepared, and in which a threshold current (DC Ic) in the self-field at a temperature of 77 K under air pressure of 1 bar 150 A to 500 A can be.

4 shows a structure of the superconducting wires according to the present invention in a sectional view, respectively.

More specifically, shows 4 (a) a sectional view of an embodiment of a superconducting wire, which can be applied to a superconducting cable according to the present invention, while 4 (b) a sectional view of another embodiment of the superconducting wire shows.

For the sake of better embodiments, the superconducting wire 131 , which builds superconducting conductor layer, explained below as an example.

In this case, the superconducting wire according to the present invention may be those of the first or the second generation.

In this regard, the case where an electric resistance at the temperature condition in which the temperature is less than a certain value goes to 'zero' is called a superconducting phenomenon, while the case where a superconducting phenomenon is used in comparison with the absolute temperature relatively high temperature, which is not equal to an absolute zero point (0 K (-273 ° C)) but close to 100 K (-173 ° C) occurs, is called a high-temperature superconductor. As the superconducting wires used in the area of the power supply cable, the high-temperature superconductors are used, even the first-generation superconducting wires having as a main material a silver (Ag) base material and BSCCO and the second-generation coated-conductor type superconducting wires presenting as main material YBCO and ReBCO were. Here, the second-generation superconducting wires mean those in which as the superconducting material provided on a deposition layer of the superconducting wires, mainly YBCO or ReBCO (Re = Sm, Gd, Nd, Dy, Ho), etc. are used.

Here, when the second generation superconducting wires are described in detail, they may be designed to have a metallic substrate layer, a deposition layer, a silver (Ag) layer, or the like. In this case, the metallic substrate layer is used as the base element of the superconducting wire and serves to maintain the mechanical strength of the superconducting wires, with a material such. As Hastelloy, nickel-tungsten (Ni-W), etc. can be used. Further, the deposition layer has a buffer layer for depositing a superconducting layer on the metal substrate, and a superconducting layer, which is used as a current-carrying path of an electric current in turn-on.

Further, the silver (Ag) layer may consist of a silver (Ag) or copper (Cu) alloy layer. At this time, the silver (Ag) alloy layer is located between the superconductive layer and the copper (Cu) alloy layer and may allow deposition, whereby the copper (Cu) alloy layer may play a role of enhancing mechanical strength. Furthermore, depending on the application device, the respective alloy layers may be designed differently with regard to their thickness or their material, wherein they have the properties in which the electrical conductivity exists at the normal temperature.

However, the in 4 According to the present invention, the superconducting wires according to the present invention are those of the second generation, for which superconducting wires using a metallic substrate layer of Hastelloy, nickel-tungsten (Ni-W) alloy material can be used. Essentially shows 4 specifically, an example in which two types of superconducting wires are used.

Thereby, the superconducting wire according to the present invention having a width of 0.4 mm to 0.5 mm and a thickness of 0.3 mm to 0.5 mm can be provided, and by using a superconducting material such as YBCO or ReBCO (Re = Sm, Gd, Nd, Dy, H 2 O), and in which a threshold current (DC Ic) in its own field at a temperature of 77 K under atmospheric pressure of 1 bar 150 A to 500 A, wherein under the Self-field is understood to be an electromagnetic environment, which is generated by an electrical current flowing through the wire itself.

In this case, the threshold current can be measured by means of a continuous measuring method at a distance of about 0.5 m to 1 m on a superconducting wire to be measured. In this case, the threshold current is understood to be a maximum current (before the short circuit, such as extinction, etc.), which can flow through the application of a permanent DC voltage (DC).

In this regard shows 4 (a) a superconducting wire 131 in which a superconducting material of YBCO system is used during 4 (b) a sectional view of a superconducting wire 131 shows, in which a superconducting material of a ReBCO system is used.

Furthermore, the material of a metallic substrate layer 1311 that the in 4 (a) shown, superconducting wire 131 is a nickel-tungsten (Ni-W) alloy, wherein the metallic substrate layer 1311 can be configured in the form of a band of metal.

Above the metallic substrate layer 1311 made of a nickel-tungsten (Ni-W) alloy material, a deposition layer comprising a plurality of buffer layers may be applied 1312 . 1313 and 1314 and a superconducting layer 1315 made of a YBCO material.

When in 4 (a) illustrated embodiment, are three layers of buffer layers 1312 . 1313 and 1314 More specifically, each layer that constructs the buffer layers may be more specifically formed of a layer of a material such as Y 2 O 3, YSZ, CeO 2, etc. This is a superconducting layer 1315 deposited from a YBCO material above each buffer layer, wherein on an outer side of the superconducting layer 1315 a silver (Ag) layer for the purpose of protecting the superconducting wires, etc. as a silver (Ag) layer 1316 can be applied.

Furthermore, the electrically conductive layer me1 or me2 respectively above and below the in 4 (a) shown, superconducting wire 131 , ie in each case on an outer side of the substrate layer 1311 and at the silver (Ag) layer 1316 be upset.

The reason why the electrically conductive layer me1 or me2 respectively on the two sides of the superconducting wire 131 is more to reinforce the physical rigidity more, to minimize the deviation of the physical properties depending on the bending direction, and to be able to increase the capacity of the electrically conductive layer as a return conductor more than at the case where an electrically conductive layer is provided on only one side, as mentioned above.

Further, the superconducting wire 131 each having a superconducting conductor layer or a superconducting screen layer, is formed such that its current guiding function according to the design capacity is implemented under such a condition that the superconducting condition is maintained, the electric current passing through the superconducting wire 131 flows, but is then passed through the above-described shaped body, when the superconducting condition due to the problem of the system, etc., is destroyed, and wherein the diameter of the shaped body or the number of conductor strands, etc. are determined according to the capacity for switching through the electrical fault current can.

As the diameter of the molding 110 However, if the diameter of the entire superconducting cable is ultimately decisively determined, the diameter of the shaped body must be reduced in preparation for the passage of the electrical fault current, so that the diameter or the weight of the entire superconducting cable can be reduced.

As in 4 is shown, the electrically conductive layer me1 or me2 of a metal material, for. B. of a brass material therefore each above and below the superconducting wire 131 provided, so that the rigidity of the superconducting wire 131 be reinforced while the electrically conductive layer can be used as a return conductor, which can consequently lead to the minimization of the diameter, etc. of the molding.

In this case, the electrically conductive layer me1 or me2 can be configured from a metal material in a form of the metallic thin-film layer, more precisely consist of a brass material.

By brass is meant an alloy produced by adding a zinc to the copper, such an electrically conductive layer being replaced by a copper alloy having good electrical conductivity other than the brass.

Therefore, it is advantageous that an electrically conductive layer of brass should be understood as a concept comprising a copper alloy other than the brass.

In this case, the electrically conductive layer me1 or me2 may be added from the metal material, ie, brass material, in the form of the metallic thin film layer of the brass, etc., and this brass thin film layer may have a thickness of 0.1 mm to 0.2 mm. If it were assumed here that a thickness of an electrically conductive layer is made of a metal material attached to one side of the superconducting wire 131 in the form of the brass band is added 0.125 mm, then a thickness of the entire, superconducting wire 131 about 0.4 mm.

However, it has been found that when the thickness of the at least one side of the superconducting wire 131 applied, electrically conductive layer of the metal material is 0.1 mm or smaller, then it might be difficult to sufficiently strengthen the rigidity of the superconducting wire, while if the thickness is 0.2 mm or larger, then the problem could arise that the electrically conductive layer of the metal material is separated during bending from the superconducting wire and the thickness of the entire superconducting wire 131 becomes overly thicker.

For example, it may be provided in one embodiment that when the thickness of the superconducting wire 131 is about 0.1 mm, then it may be 0.35 mm by adding the electrically conductive layer of the metal material in the brass band shape having the thickness of 0.125 mm, for example, on the two sides of the superconducting wire, ie by three to can be increased four times, but the entire thickness is less than 1 mm and thus sufficiently small, so that it affects the entire thickness of the superconducting cable negligible. Nevertheless, the stiffness of the superconducting wire 131 reinforced and also used as a return conductor of the electrical fault current, which can consequently lead to the reduction of the diameter or weight of the molding.

In other words, the electrically conductive layer me1 or me2 is made of the brass material as the metallic thin film layer respectively above and below the superconducting wire 131 provided, so that the rigidity of the superconducting wire 131 at the same time, the diameter or the weight of the molding can be reduced, which means that when the electrically conductive layer having a predetermined thickness is provided on the outside of the metallic substrate layer and on the outside of the silver (Ag) layer, Then, the diameter or the weight of the shaped body can be reduced relatively more than in the case where the electrically conductive layer is not on the superconducting wire 131 is provided.

In this way, the attached, electrically conductive layer me1 or me2 must be electrically connected the superconducting wire 131 be connected, so when the occurrence of an electric leakage current in a state in which the electrically conductive layer me1 or me2 by means of soldering, etc. respectively on the two sides of the superconducting wire 131 attached, the electrical current passing through the superconducting layer of the deposition layer 1315 flows, can now flow through the electrically conductive layer me1 or me2.

In this regard, is in 4 therefore, the process is essentially not represented by which the superconducting wire 131 and the electrically conductive layers me1 and me2, on the two sides of the superconducting wire 131 are mounted, are connected in parallel to each other for switching through the electrical fault current, and by means of which the superconducting wire 131 and the electrically conductive layers me1 and me2, on the two sides of the superconducting wire 131 are attached, each electrically connected to each other. However, another method may be used by which means the lateral side of the superconducting wire 131 is soldered with a metal-based solder, or by means of which the superconducting wire 131 with a metal with a good electrical conductivity, z. B. copper (Cu) is plated.

By means of the above two methods can increase the thickness or volume of the superconducting wire 131 to which the electroconductive layers me1 and me2 are attached are minimized, and thus the electrically conductive layers me1 and me2 and the superconducting wire 131 electrically connected to each other.

Be the metallic substrate layer 1311 that the such superconducting wire 131 builds up the deposition layers 1312 to 1315 with the superconducting layer, and the silver (Ag) layer 1316 By means of the copper plating or the lateral soldering in each case electrically connected in parallel to each other, then the superconducting layer 1315 electrically with the metallic substrate layer 1311 , the silver (Ag) layer 1316 and the respective electrically conductive layers me1 and me2, wherein the electrically fault current is adjacent to the electrically conductive layers me1 and me2 except for the metallic substrate layer 1311 and the silver (Ag) layer 1316 can be distributed.

In addition, the electroconductive layers me1 and me2 may be used as a metallic thin film layer by means of soldering to the superconducting wire 131 be attached. In this case, the solder for soldering the electrically conductive layers me1 and me2 on the other sides of the superconducting wire 131 of tin (Sn), lead (Pb) and silver (Ag), and its melting point may be 200 ° C or lower. However, in addition to such solder materials, the metallic substrate layer 1311 or the silver (Ag) layer 1316 containing the electrically conductive layers me1 and me2 and the superconducting wire 131 can be mounted electrically conductive, then also different soldering or attachment methods can be applied.

4 (b) shows a superconducting wire 131 ' in which a superconducting material of a ReBCO system is used. It is on the repetition of the same versions as in the embodiments according to 4 (a) waived.

Here, the material of the metallic substrate layer 1311 ' that the in 4 (b) shown, superconducting wire 131 ' is a nickel-tungsten (Ni-W) alloy, wherein the metallic substrate layer 1311 ' may also be configured in the form of a metallic thin film layer.

Above the metallic substrate layer 1311 ' made of a nickel-tungsten (Ni-W) alloy material may have a deposition layer 1312 ' to 1317 ' be provided, the at least six-layer buffer layers 1312 ' . 1313 ' . 1314 ' . 1315 ' and 1316 ' and a superconducting layer 1317 ' a ReBCO system, wherein on an outer side of the deposition layer 1312 ' to 1317 ' a silver (Ag) layer as a silver (Ag) layer 1318 ' can be applied.

In this case, each sheath layer, the buffer layers 1312 ' . 1313 ' . 1314 ' . 1315 ' and 1316 ' consist of Al2O3, Y2O3, IBAD-MGo, EPI-MGo and LaMoO3 layers.

Also the in 4 (b) shown, superconducting wire 131 ' can, as well as in the 4 (a) In the illustrated superconducting embodiment, it is used to enhance the physical strength and to distribute the electrical leakage current such that the respective electrically conductive layers me1 and me2 are respectively formed on the outer sides of the metallic substrate layer 1311 ' and the silver (Ag) layer 1318 ' are provided.

In this way, the diameter of the shaped body, which can take a role as a return conductor of the electrical fault current, can be reduced by means of the method, by means of which at the two of the superconducting wire 131 ' each an electrically conductive layer consisting of a metallic thin film layer of a material such. As brass, etc., constructed and used as a means for switching through the electrical fault current.

Of course, the metallic substrate layer and the silver (Ag) layer, which are the same as in 4 shown superconducting wire 131 ' However, the sectional areas of the metallic substrate layer and the silver (Ag) layer were not large in thickness of the conventional superconducting wires, and thus the bypass capacitance of the electric leakage current was slight.

However, as described above, the electroconductive layers me of a metal material each have a dice of about 0.125 mm, which is why the current carrying capacity through these layers may affect the diameter of the molded body for taking over the role as the return path of the electric leakage current.

In dimensioning the diameter of the molded article, therefore, this diameter can be set to be, together with the electrically conductive layers, of a metal material of the superconducting wires constituting the superconductive conductive layer 131 ' taking into account the current carrying capacity of the electrical fault current through the metallic substrate layer and the silver (Ag) layer can be reduced even more than before. In this case, a maximum allowable amount of current can be evaluated by means of a method for thermal analysis based on the through-connection of the electrical fault current through the metallic substrate layer and the silver (Ag) layer, and thus the diameter of the shaped body can be dimensioned correspondingly reduced.

5 shows a tester for Beigeprüfung a superconducting wire according to the present invention. Specifically shows 5 (a) A device for measuring a threshold current when applying a bending load while 5 (b) shows a device for measuring a threshold current when applying a double bending load.

The threshold current in applying a bending load is by bending the superconducting wire 131 measured in the opposite direction over two rollers, while the threshold current when applying a double bending load also by bending the superconducting wire 131 measured in the opposite direction over four rollers.

When the superconducting wire according to the present invention was formed to have a thickness of 3y to 5y, as in FIG 3 (b) in which the thickness of the superconducting wire 131 to which the electroconductive layers me1 and me2 are attached from a brass material, it has been found that a tensile strength of the superconducting wire to which the electroconductive layers are added as a metallic thin film layer having the electric conductivity at the normal temperature , 200 Mpa to 800 Mpa with respect to a 95-percent current damping (English: IC relentation) can be and thus sufficient rigidity when winding the superconducting wire can be obtained on the surpraleitende cable.

Incidentally, the scale of the 95% current leakage (ICrelentation) is a test method by which, by gradually increasing a clamping force on both ends of the superconducting wire, the clamping force is measured until the 95% current amount of the output efficiency can be obtained. This therefore means that even when applying the clamping force of 200 Mpa (megapascal) to 800 Mpa on the superconducting wire at least 95-percent current capacity can be obtained. On the other hand, these conditions mean that the tests are carried out by means of the in 5 shown test method, etc. can be passed. Ie. For example, the method that will be described below is the one that can serve to verify that a threshold current can meet 95 percent of a normal threshold current of a superconducting wire after the physical or electrical properties have been pre-set on the load conditions.

As in 5 (a) 1, the threshold current during application of a bending load after the successive directional bending of the superconducting wire provided with the metal laminates according to the invention by means of two rollers r1 and r2, each with a diameter of 35 mm, satisfies the conditions exceeding 95 percent of the threshold current of the superconducting wire go out without bending load.

As in 5 (b) represented, the threshold current when applying a double bending load after successive directional bending of the superconducting wire provided with the metallic layer layers according to the invention by means of four rollers r1, r2, r3 and r4, each with a diameter of 50 mm, the conditions over the 95 Percent of the threshold current of the superconducting wire go out without bending load.

As described above, according to the present invention, the superconducting wire is provided with the metallic film layers so that it obtains sufficient physical strength during the manufacturing and laying operation, and thus in addition to the bending load Applying a tensile stress and torsional stress can meet the conditions that exceed the 95 percent of the threshold current of the superconducting wire without tensile stress and torsional stress.

Concretely, the superconducting wire according to the present invention may be formed such that its threshold threshold current when applying a longitudinal clamping force of 250 MPa or 0.2% elongating clamping force to it is also 95% or more of the above normal threshold current, and its twist threshold current in a state of being twisted 200 mm apart in a longitudinal direction is also 95% or more of the above normal threshold current.

Further, it is preferable that, with respect to the torsion stress, the torsional threshold current of the superconducting wire according to the present invention in a state where it is twisted 200 mm apart in a longitudinal direction, 95 percent or more of the threshold current of a superconducting wire without Twist is.

Furthermore, it is advantageous that the superconducting wires 131 are usually joined together within the distance of 1 kilometer three times or less to reduce contact resistance. Thereby, the superconducting wires are joined to each other with a unit of 200 m to 400 m, and an electric resistance of a joint may be 200 nΩ or less (eg, 100 nΩ to 200 nΩ).

In addition, it is preferable that an AC loss of the superconducting wire according to the present invention is 0.4 W / kA · m or less. In this case, this AC loss means that the loss resulting from switching through an AC current of 1 kA by the single superconducting wire having a length of 1 m must be 0.4 W or less. This does not dictate a portion of the ac current of a superconducting cable but a single superconducting wire.

In addition, it is advantageous that even with the simultaneous application of the clamping force and rotation, the conditions of the threshold current and the resistance in the joint must be met on the basis of the same criteria.

In this connection, the superconducting wires according to the present invention may be joined along the longitudinal direction of a cable in the longitudinal direction, and the contact resistance per joint may be 200 nΩ or less. However, it is assumed that this contact resistance is measured in a state where the superconducting wire is not loaded with the stress, and it is also preferable that the resistance per joint of the superconducting wire is not increased by 20% or so even in a state is increased more, in which the superconducting wires loaded with the clamping force and wound on the molding, etc. of the superconducting cable.

Consequently, it is advantageous that the contact resistance also when applying a load of 3 kg to 8 kg, d. H. a tensile force, to this superconducting wire in a longitudinal direction thereof in a state in which this superconducting wire is wound on a shaped body of the superconducting cable with a pitch of more or less 220 mm, measured by 240 nΩ or less, or by only 20% or less of a normal contact resistance is increased.

Only if the electrical properties, in which the threshold current of the superconducting wire must be about 95% or more of the threshold current of the superconducting wire without load, can be satisfied, the durability and the electrical conductivity of the superconducting wires during the manufacturing process and the laying operation of the superconducting cable.

6 shows a diagram of a voltage depending on a voltage applied to the superconducting wire current.

In this case, the threshold current is understood to be a maximum current (before the short circuit, such as extinction, etc.), which can flow through the application of a permanent DC voltage (DC). If the current is switched through the threshold current, then the resistance is therefore increased suddenly and the voltage is suddenly increased. Therefore, it is not preferable that the rate of increase of the voltage is exaggeratedly excessive.

As the second-generation superconducting wire according to the present invention, the superconducting wire formed such that a gradient of an electric voltage to an electric current equal to or greater than the above normal threshold current, a range of 25 to 30 fulfilled. In this case, this gradient (n) can of course be measured by means of the method for measuring the threshold current.

7 shows a tester for testing a hermeticity of a superconducting wire according to the present invention.

The hermeticity of the superconducting wire is understood to mean that this superconducting wire is not inflated and maintained in a state of being immersed in a liquid nitrogen at high pressure, and the predetermined range of the threshold current is ensured.

In this case, a test method can be used, by means of which a visual inspection and a measurement of a threshold current are carried out after a metal tube (s) in which the superconducting wire 131 is inserted, was filled with the liquid nitrogen (L) and then the state in which the pressure by means of a gaseous nitrogen from the outside into the inside of the metal tube (s) is applied so that the internal pressure of the metal tube (s) about 30 atm can be maintained for 16 hours, as in 7 shown.

If the superconducting wire is not inflated under these test conditions in the visual inspection and its threshold current in the range of about 95 percent of a conventional threshold current is obtained, then it can be seen so that the hermeticity of the superconducting wire is met.

As described above, the present description has been explained with reference to the preferred embodiments of the invention. However, one skilled in the art will variously modify and change the invention without departing from the spirit and scope of the invention as described in the following claims. If the varied embodiments therefore basically comprise the components of the claims according to the invention, then they should also be regarded as included in the technical scope of the invention.

Claims (15)

A superconducting wire having a width of 0.4 mm to 0.5 mm and a thickness of 0.3 mm to 0.5 mm, and using a superconducting material such as YBCO or ReBCO (Re = Sm, Gd, Nd, Dy, HO), characterized in that a threshold current (DC Ic) of the superconducting wire in the self-field at a temperature of 77 K under atmospheric pressure of 1 bar is 150 A to 500 A. A superconducting wire according to claim 1, characterized in that after the superconducting wire is successively bent directionally by means of two rollers each having a diameter of 35 mm, its threshold current when applying a bending load is 95% or more of the threshold current in the self field. A superconducting wire according to claim 1, characterized in that after the superconducting wire is successively bent by four rolls each having a diameter of 50 mm, its threshold current when applying a double bending load is 95% or more of the self-threshold threshold current. A superconducting wire according to claim 1, characterized in that it is designed so that its threshold threshold current when applying a longitudinal clamping force of 250 MPa or 0.2% elongating longitudinal force to it is 95% or more of the self-threshold threshold current. A superconducting wire according to claim 1, characterized in that it is formed such that its torsional threshold current in a state of being twisted 200 mm apart in a longitudinal direction is 95% or more of the self-threshold threshold current. A superconducting wire according to claim 1, characterized in that a threshold current of the superconducting wire when applying a load of 3 kg to 8 kg to said superconducting wire in a longitudinal direction thereof in a state where said superconducting wire is provided on a molded body of said superconducting cable Slope of more or less wound by 220 mm, 95 percent or more of the threshold current is in the self field. A superconducting wire according to claim 1, characterized in that it is formed such that a plurality of wires having a unit of 200 m to 400 m are joined to each other, wherein an electrical resistance of a joint 200 nΩ or less. A superconducting wire according to claim 7, characterized in that a joint resistance of the joint is selected such that this joint resistance per joint to which the load of 3 kg to 8 kg is applied in a longitudinal direction in a state where the superconducting wire is placed on a Shaped body of the superconducting cable with a pitch of more or less by 220 mm, 240 nΩ or less, or is increased by 20 percent or less compared to a joint resistance of a normal state. A superconducting wire according to claim 1, characterized in that it is formed such that its threshold current is in a state of being in a liquid nitrogen at the atmospheric pressure of 30 atm submerged for 16 hours, is 95 percent or more of the threshold current in the self field. A superconducting wire according to claim 1, characterized in that the superconducting wire is not visually observed to be inflated in a state of being immersed in a liquid nitrogen maintaining an internal pressure of about 30 atm for 16 hours. A superconducting wire according to claim 1, characterized in that a gradient of an electric voltage to an electric current equal to or greater than the self-threshold threshold current is 25 to 30. A superconducting wire according to claim 1, characterized in that an AC loss of the superconducting wire is 0.4 W / kA · m or less. A superconducting wire having a width of 0.4 mm to 0.5 mm and a thickness of 0.3 mm to 0.5 mm, and using a superconducting material such as YBCO or ReBCO (Re = Sm, Gd, Nd, Dy, HO), characterized in that a threshold current (DC Ic) in the self-field at a temperature of 77 K under atmospheric pressure of 1 bar 150 A to 500 A; in the following cases, a threshold current satisfactorily achieves 90 percent or more of self-field threshold current (DC Ic): namely, in the case where a bending load after successively changing the direction of the above superconducting wire by means of two rollers each having a diameter of 35 or a double bending load is applied after the successive turning of the above superconducting wire by means of four rollers each having a diameter of 50 mm or a longitudinal clamping force of 250 MPa or a wire extending by 0.2% Longitudinal clamping force is applied to the above superconducting wire, or in which the above superconducting wire is twisted by a distance of 200 mm in a longitudinal direction, or at a load of 3 kg to 8 kg in a state in which this superconducting wire on a molded body of the superconducting cable with a slope of more or less around 2 20 mm is wound on the above superconducting wire in a longitudinal direction thereof or in a state where the above superconducting wire is immersed in a liquid nitrogen in which an internal pressure of about 30 atm is maintained for 16 hours; that the superconducting wire is formed so as to join a plurality of wires having a unit of 200 m to 400 m, with an electrical resistance of a joint 200 nΩ or less, and wherein the joint resistance of the joint is selected such that this joint resistance per Joint to which the load of 3 kg to 8 kg is applied in a longitudinal direction in a state in which the above superconducting wire is wound on the molded body of the superconducting cable with a pitch of more or less by 220 mm, 240 nΩ or less is increased or increased by 20 percent or less compared to a joint resistance of a normal state; that a gradient of an electric voltage to an electric current equal to or greater than the self-threshold threshold current is 25 to 30; and that an AC loss of the superconducting wire is 0.4 W / kA · m or less. A superconducting wire having a width of 0.4 mm to 0.5 mm and a thickness of 0.3 mm to 0.5 mm, and using a superconducting material such as YBCO or ReBCO (Re = Sm, Gd, Nd, Dy, HO), characterized in that the inflation of the above superconducting wire in a state of being in a liquid nitrogen in which an internal pressure of about 30 atm is maintained, immersed for 16 hours is not visually observed. A superconducting wire having a width of 0.4 mm to 0.5 mm and a thickness of 0.3 mm to 0.5 mm, and using a superconducting material such as YBCO or ReBCO (Re = Sm, Gd, Nd, Dy, HO), characterized in that a threshold current (DC Ic) in the self-field at a temperature of 77 K under atmospheric pressure of 1 bar 150 A to 500 A; in the following cases, a threshold current satisfactorily achieves 90 percent or more of self-field threshold current (DC Ic): namely, in the case where a bending load after successively changing the direction of the above superconducting wire by means of two rollers each having a diameter of 35 or a double bending load is applied after the successive turning of the above superconducting wire by means of four rollers each having a diameter of 50 mm or a longitudinal clamping force of 250 MPa or a wire extending by 0.2% Longitudinal clamping force is applied to the above superconducting wire, or in which the above superconducting wire is twisted by a distance of 200 mm in a longitudinal direction, or at a load of 3 kg to 8 kg in a state in which this superconducting wire on a molded body of the superconducting cable with a slope of more or less around 2 20 mm is wound on the above superconducting wire in a longitudinal direction thereof or in a state where the above superconducting wire is immersed in a liquid nitrogen in which an internal pressure of about 30 atm is maintained for 16 hours; that the superconducting wire is formed so as to join a plurality of wires having a unit of 200 m to 400 m, with an electrical resistance of a joint 200 nΩ or less, and wherein the joint resistance of the joint is selected such that this joint resistance per Joint to which the load of 3 kg to 8 kg is applied in a longitudinal direction in a state in which the above superconducting wire is wound on the molded body of the superconducting cable with a pitch of more or less by 220 mm, 240 nΩ or less is increased or increased by 20 percent or less compared to a joint resistance of a normal state; that a gradient of an electric voltage to an electric current equal to or greater than the self-threshold threshold current is 25 to 30; that an AC loss of the above superconducting wire is 0.4 W / kA · m or less; and that the inflation of the above superconducting wire in a state of being immersed in a liquid nitrogen in which an internal pressure of about 30 atm is maintained for 16 hours is not optically observed.

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